DO NORMAL EARLY COLOR-FLOW DUPLEX SURVEILLANCE EXAMINATION RESULTS OFINFRAINGUINAL VEIN GRAFTS PRECLUDE THE NEED FOR LATE GRAFT REVISION

Purpose: Optimal duration of postoperative duplex surveillance of infr ainguinal vein grafts is not known. Previous reports have suggested ne arly all vein graft stenoses are present within the first postoperativ e year, and normal duplex examination results during this time elimina te the need for ongoing graft surveillance. To determine whether surve illance may be safely discontinued in patients with normal early posto perative surveillance studies, we reviewed the color-flow surveillance examinations in our patients who underwent infrainguinal reverse vein graft revisions during a 41/2 year period. Methods: Clinical and vasc ular laboratory records were reviewed of all patients who underwent in frainguinal reverse vein bypass grafting followed by subsequent graft revision for a duplex scanning-detected abnormality at our institution between January 1990 and July 1994. Results: Of 447 infrainguinal rev erse vein bypasses performed, 36 (8.1%) underwent surgical revision as a result of an abnormal finding during routine duplex surveillance. T he initial postoperative duplex examination was obtained within 2 week s of graft implantation in 23 (64%) patients, between 2 weeks and 3 mo nths in 10 (28%) patients, and between 3 and 6 months in three (8%) pa tients. Duplex abnormalities prompting revision included 11 (31%) graf ts with a mid-graft peak systolic velocity (PSV) less than or equal to 45 cm/sec, 23 (64%) grafts with a focal PSV greater than or equal to 200 cm/sec, one graft with a PSV greater than or equal to 150 cm/sec b ut < 200 cm/sec, and one thought to be occluded by duplex but found to be patent by angiography. Abnormal duplex findings were initially det ected within 2 weeks of graft implantation in five (14%) patients, bet ween 2 weeks and 3 months in eight (22%) patients, from 3 to 6 months in 12 (33%) patients, from 6 to 12 months in six (17%) patients, and > 1 year in five (14%) patients. In only 25% of cases were mid-graft PS Vs less than or equal to 45 cm/sec or focal velocities greater than or equal to 200 cm/sec identified on the initial examination; 75% were f ound during subsequent surveillance. Conclusions: Although most revers e vein graft abnormalities detected by duplex surveillance and prompti ng graft revision appear within the first postoperative year, many are not detected on the initial examination. In our recent experience 31% of duplex abnormalities leading to vein graft revision were first det ected more than 6 months after operation. Discontinuation of graft sur veillance based on normal early findings will result in thrombosis of some vein grafts that may otherwise be salvaged.